:root {
    color-scheme: light;
    --page-bg: #f4f7f6;
    --surface: #ffffff;
    --text: #1f2933;
    --muted: #66737f;
    --border: #d9e2e0;
    --primary: #176b55;
    --primary-hover: #105542;
    --danger-bg: #fff0f0;
    --danger-border: #e7a9a9;
    --danger-text: #8a1f1f;
}

* { box-sizing: border-box; }
html, body { min-height: 100%; }
body {
    margin: 0;
    background: var(--page-bg);
    color: var(--text);
    font-family: system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
}

.site-header {
    min-height: 64px;
    padding: 12px 24px;
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 20px;
    background: var(--surface);
    border-bottom: 1px solid var(--border);
}

.brand {
    color: var(--primary);
    font-size: 1.25rem;
    font-weight: 750;
    text-decoration: none;
}

.header-user,
.header-user form {
    display: flex;
    align-items: center;
    gap: 12px;
}

.page-shell {
    width: min(1100px, calc(100% - 32px));
    margin: 32px auto;
}

.site-footer {
    padding: 24px;
    color: var(--muted);
    text-align: center;
}

.auth-layout {
    min-height: calc(100vh - 180px);
    display: grid;
    place-items: center;
}

.card {
    width: min(100%, 440px);
    padding: 28px;
    background: var(--surface);
    border: 1px solid var(--border);
    border-radius: 14px;
    box-shadow: 0 14px 36px rgba(20, 43, 37, 0.08);
}

.card-wide { width: min(100%, 850px); }
.card h1 { margin: 0 0 8px; font-size: 1.6rem; }
.card p { color: var(--muted); }

.form-grid { display: grid; gap: 18px; }
.field { display: grid; gap: 7px; }
.field label { font-weight: 650; }
.field input[type="text"],
.field input[type="email"],
.field input[type="password"] {
    width: 100%;
    padding: 11px 12px;
    border: 1px solid var(--border);
    border-radius: 9px;
    background: #fff;
    color: var(--text);
    font: inherit;
}
.field input:focus {
    outline: 3px solid rgba(23, 107, 85, 0.16);
    border-color: var(--primary);
}
.checkbox-row { display: flex; align-items: center; gap: 9px; }

.button {
    display: inline-flex;
    justify-content: center;
    align-items: center;
    min-height: 42px;
    padding: 9px 16px;
    border: 1px solid transparent;
    border-radius: 9px;
    cursor: pointer;
    font: inherit;
    font-weight: 700;
    text-decoration: none;
}
.button-primary { background: var(--primary); color: #fff; }
.button-primary:hover { background: var(--primary-hover); }
.button-secondary { background: #fff; color: var(--text); border-color: var(--border); }

.alert-error {
    margin: 0 0 18px;
    padding: 12px 14px;
    border: 1px solid var(--danger-border);
    border-radius: 9px;
    background: var(--danger-bg);
    color: var(--danger-text);
}

.definition-grid {
    display: grid;
    grid-template-columns: minmax(150px, 220px) 1fr;
    gap: 10px 20px;
}
.definition-grid dt { color: var(--muted); }
.definition-grid dd { margin: 0; overflow-wrap: anywhere; }

.code-list {
    margin: 0;
    padding-left: 20px;
    font-family: ui-monospace, SFMono-Regular, Menlo, Consolas, monospace;
}

@media (max-width: 640px) {
    .site-header { align-items: flex-start; flex-direction: column; }
    .header-user { width: 100%; justify-content: space-between; }
    .definition-grid { grid-template-columns: 1fr; }
}